select s.specification_id c.contract_id from specification s join contract c on (s.contract_id=c.contract_id) join usr u on (c.contragent_id=u.contragent_id) where u.usr_id= order by specification_id desc limit 1; select u.usr_id k.contragent_id from usr u left outer join contragent k on u.contragent_id=k.contragent_id where u.usr_id=